Mechanical flexure for motion amplification and transducer with same

ABSTRACT

A mechanical flexure element useful for motion amplification with a closed end and two legs extending therefrom in a general U-shaped configuration. One leg may be fixed and the other leg moved, or both legs may be movable with respect to each other. Microdisplacements of a leg are amplified and translated into larger transverse movements of the closed end. Reversing the input and output displacements provides attenuation of a larger input displacement. A magnetostrictive electromechanical transducer with a flexure element having a closed end and two legs extending thereform moving towards and away from a nozzle in an enclosed nozzle chamber under fluid pressure. An electrical input signal actuates a magnetostrictive element coupled to one leg of the flexure element to move the element with respect to the nozzle thereby changing the fluid output pressure from the nozzle chamber. Diaphragm means are coupled to the moving leg of the flexure element and responsive to the changing pressure in the nozzle chamber to provide a feedback force until the final fluid output pressure is proportional to the electrical input signal.

This is a division of application Ser. No. 07/723,698 filed Jun. 26,1991, now U.S. Pat. No. 5,163,463, which in turn is a continuation ofSer. No. 07/554,339 filed Jul. 19, 1990, now abandoned.

This invention relates to a mechanical flexure element for motionamplification and to electromechanical transducer devices incorporatingsuch a mechanical flexure element.

BACKGROUND OF THE INVENTION

Reference may be made to the following U.S. patents of interestconcerning mechanical flexure elements: U.S. Pat. Nos. 4,748,858;3,638,481; 3,370,458; 3,151,693; 3,848,462; 2,963,904.

In many applications, it is desired to provide a flexure element thatcan be used to amplify or increase small motions into larger motions.One example of such a desirable use for such a device is ininstrumentation where for example a sensing element is subjected to orundergoes a slight displacement which is to be detected to provide amotion indication or a quantitative motion measurement. Such motionamplification devices are extremely desirable for example for use withpiezoelectric, magnetostrictive, or electrostrictive elements, and othersuch types of transducers in the detection or sensing of very smalldisplacements in the micron range, i.e., micro-meter range.

Present motion amplification devices such as lever mechanisms suggestedfor micro-meter range sensing have major drawbacks in certain areas suchas reaction to temperature changes, fragile structure, low motionamplification, high lost motion characteristics, high hysteresis losses,or costly materials or method of manufacturing. Accordingly, it isdesired to provide a mechanical flexure which can be sized to amplifyvery small, micron displacements generated for instance bymagnetostrictive, electrostrictive and piezoelectric elements, so as tobe adaptable for use in practical actuator and transducer units andwhich desirable flexure element provides the following advantages overconventional lever mechanisms: (1) simple, low-cost structure and methodof manufacture; (2) providing high amplification ratio for very smalldisplacements; (3) significantly reduced lost motion characteristics;(4) very linear for small displacements; (5) low hysteresis; (6) lowsensitivity to temperature changes; and (7) rugged, reliable structurewith long lasting performance.

Reference may also be made to the following U.S. patents of interestwith respect to electromechanical transducers: U.S. Pat. Nos. 4,701,660;4,158,368; 4,025,942; 3,370,458; 3,218,445; 2,992,373; 2,904,735;2,769,867; 2,419,061; and to the publication, "Application Manual ForThe Design of Etrema TERFENOL-D™ Magnetostrictive Transducers", J. L.Butler, Edge Technologies, Inc. 1988.

Electromechanical transducers have been used for many years totransform, for instance, electrical signals into a mechanical motion,and vice versa. Such transducers find application in a variety ofcircumstances, including fluid flow control devices, fluid flowindicating and measuring devices, etc. A particular need is desired fora reliable electromechanical transducer which can respond to very smallelectrical signals to provide micro-motion in a transducer element or amoving member connected to the transducer element. Priorelectromechanical transducers have utilized piezoelectric substances,Rochelle salt, or electrostrictive materials, such as polycrystallineceramics.

Recently, in the desire to obtain more sensitive and faster actingelectromechanical transducers, the introduction of magnetostrictivematerials to such transducers has been proposed, such as is disclosed inthe above indicated U.S. Pat. No. 4,158,368. This patent proposes theuse of a magnetostrictive material with coupled members movable by themagnetostrictive material when placed in a magnetic field. Severalembodiments are illustrated in this patent including, a valve plunger, aplate having apertures in another valve configuration, and two slidingplates with apertures selectively alignable in another valveconfiguration.

It is desirable to provide an electromechanical transducer for sensingand producing micro-motions in a more simple structural and operatingconfiguration compared to prior suggested devices.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, there isprovided a flexure element, made of metal, plastic, fiber or othersimilarly rigid material that can be used to amplify very small motionsinto larger motions and which provides all of the desired advantagesover conventional lever mechanisms. According to the principles of thepresent invention, there is provided a flexure element having a closedend and two legs extending therefrom along respective longitudinal axes.Moving a first leg in longitudinal displacement with respect to theother through displacement means coupled to the first leg provides alarger amplified transverse displacement of the closed end with respectto the longitudinal axes.

As an example, one end of one leg may be fixedly mounted in position.Moving the other leg by for instance small longitudinal displacementsgenerated by displacement means, such as magnetostrictive,electrostrictive or piezoelectric devices attached or coupled to thelongitudinally moved leg enables the flexure or bender element to bendtowards or away from the longitudinal axes which displaces the freeclosed end transversely to the longitudinal axes. Very smalldisplacements of the moving leg, such as generated by the micron-sizeddisplacements of a magnetostrictive device in response to a magneticfield, provides an amplified larger transverse movement of the freeclosed end of the flexure element. Thus, small longitudinal legdisplacements are translated into much larger closed end displacementstransverse to the longitudinal axis. Amplification ratios of 30/1 havebeen obtained in constructed embodiments of a bender element accordingto this invention.

A unique bender element in accordance with the present invention can beutilized in electromechanical transducers, such as a current to pressuretransducer, in an electro-pneumatic relay, and in a control valveactuator. In particular, the flexural or bender element of the presentinvention provides a very simple, low-cost flexure device with a highamplification ratio, very linear output movements for smalldisplacements, very low lost motion characteristics, low hysteresis, lowsensitivity to temperature changes, and is rugged, reliable and capableof providing long lasting performance.

In another aspect of the present invention, there is provided anelectromechanical transducer incorporating a bender device of thepresent invention. A current to pressure transducer is one embodiment ofthis invention, and includes a bender element to amplify micron-sizeddisplacement from a magnetostrictive element. Current flowing throughthe coil of the magnetostrictive material causes the material toelongate. The motion of the magnetostrictive element is transmitted tothe bender device, causing the free closed end of the bender device tomove with greatly amplified motion.

The current to pressure transducer includes a nozzle chamber with theflexure or bender element mounted so as to control the fluid pressurepassing from the nozzle chamber through the nozzle. Thus as the flexureelement moves, pressure in the nozzle chamber may increase. Thisincreased nozzle chamber pressure acts upon a feedback diaphragmattached to the flexure element and the magnetostrictive material todevelop a compressive force which tends to restore the magnetostrictivematerial to its original length. When the feedback force exerted on thediaphragm equals the electrical input force generated through themagnetostrictive element, the resulting output pressure from the nozzlechamber is proportional to the magnetostrictive element coil inputcurrent.

Other forms of electromechanical transducers with the flexure or benderelement of the present invention can be provided. Piezoelectric orelectrostrictive elements can be utilized rather than a magnetostrictiveelement.

The flexure or bender element of this invention also can be used withother force or pressure elements, such as bellows, bourdon tubes,diaphragms, solenoids, voice coils, etc., for inducing small primarymotions in a flexure leg which are translated and amplified into largermovements of the closed end of the flexure element. In addition tomotion amplification, the flexure element also can be adapted for loadamplification. Outputs with large motion displacements but low forcescan be converted into outputs of high loading with small motiondisplacements.

Motions also can be attenuated using the flexure element. For instance,large displacement motions input to the flexure element closed end canbe converted into extremely accurate small movements of a flexure legsuitable for precise object positioning, measurements, etc.

A flexure or bender device according to the invention may have one fixedleg and one movable leg, or may have both legs movable with respect toeach other. Both embodiments, of course, utilize one leg movable inelongated displacement with respect to the other le(g with resultingmotion amplification and translation of the closed end of the benderdevice, or the reverse, i.e., large displacements of the closed end witha resulting attenuated motion displacement of one leg with respect tothe other.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of this invention which are believed to be novel are setforth with particularity in the appended claims. The invention may bebest understood by reference to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals identify like elements in the several figures and in which:

FIG. 1 is a perspective view illustrating a flexure or bender deviceaccording to one aspect of the invention;

FIG. 2 is a schematic view illustrating a magnetostrictiveelectromechanical transducer utilizing the flexure device of FIG. 1 inone operating position;

FIG. 3 illustrates the magnetostrictive electromechanical transducer ofFIG. 2 with the flexure device in a second operating position;

FIG. 4 illustrates an alternative electromechanical transducerembodiment;

FIGS. 5-9 illustrate alternative applications utilizing the flexuredevice of FIG. 1;

FIG. 10 illustrates an alternative flexure or bender device according tothe invention; and

FIG. 11 illustrates another alternative application utilizing theflexure device of FIG. 1.

DETAILED DESCRIPTION

Referring now to FIG. 1, there is illustrated a flexure elementconstructed in accordance with the present invention. Flexure or benderelement 10 is formed of metal, plastic, fiber or other similarly rigidmaterial into a member with closed end 12 and respective legs 14, 16extending therefrom. End 18 of leg 14 is fixed in position such asschematically illustrated by a fixed mounting block 20 to a groundreference 22. End 24 of opposite leg 16 is mounted to a movable member26 which can be a part of or connected to a magnetostrictive,electrostrictive or piezoelectric device or to a force or pressureelement providing very small, micron-sized longitudinal displacements ofleg 16.

It is to be understood that these types of movable members are given asexamples, so that neither the type of movable member, the size of theflexure element, nor the amount of flexure element movement is to betaken as a limitation of the present invention.

Thus, for example, a magnetostrictive device or a bellows formed asmovable member 26 can generate linear micro-displacements of leg 16 inthe directions indicated by reference arrow 28. As one example, if amagnetostrictive member or a bellows formed as movable member 26 movesleg 16 in a linear displacement in direction A shown with respect toreference arrow 28, flexural element 10 will bend so that closed freeend 12 will be displaced downwardly as indicated by direction C ofreference arrow 30. Conversely, micro-motions of leg 116 in direction Bof reference arrow 28 will bend free closed end 12 upwardly in directionD of reference arrow 32. Linear longitudinal displacements of leg 16 aretherefore translated in amplified transverse displacements of closed end12.

As shown in FIG. 1, micro-motions of leg 16 along longitudinal axis Xare translated into larger motions of free, closed end 12 along thetransverse axis Z. Motions of micron dimensions of leg 16 can result in100-1000 microns movement of closed end 12 along axis Z. As an exampleof one embodiment of the present invention, flexural element 10 wasconstructed of type 304 stainless steel material having the followingdimensions: flexure leg length--50.04 mm; flexure leg width--5.64 mm;each leg thickness--0.381 mm; and the legs being substantially adjacenteach other over their length. With micro-motion displacement of leg 16along longitudinal axis X amounting to 0.0254 mm, a correspondingtranslated displacement of free closed end 12 along transverse axis Z of0.762 mm was obtained, thereby providing an amplification ratio of 30/1.

Rather than type 304 stainless steel, any other rigid type material withlinear elastic characteristics may be utilized. Also, increasing the gapbetween legs 14, 16 tends to decrease the stiffness of the flexureelement and thereby lessen the amount of force required for primarymotion displacement of a moving leg. However, increasing the gap alsotends to reduce the amplification gain of the flexure or bender device.On the other hand, while decreasing the gap increases the gain of theflexure element, this tends to increase the overall stiffness of theflexure element to input motion so that significantly more force isrequired to obtain primary motion displacement of a moving leg.

Accordingly, if a magnetostrictive element which is a high force, verysmall motion causing device is used as the primary motion displacementmeans for a flexure leg, it would be advantageous to utilize a smallergap between legs 14, 16. Notice, for example, in FIG. 1 that the legsare closely adjacent each other generally in a tight, U-shapedconfiguration. Conversely, if a bellows element was used for primarymotion displacement of the moving leg, the low force and high motiondisplacement output of the bellows may necessitate increasing of the gapbetween legs 14, 16. These reasoned choices can readily be made by thoseskilled in the art in accordance with the teachings herein of theflexure device of the present invention. It is to be understoodtherefore that the various dimensions, sizes and movement amountsdescribed herein are for purposes of presenting a description of anembodiment of the invention and are not to be used to limit the scope ofthe invention.

Referring to FIGS. 2, 3, there is illustrated an electromechanicaltransducer in the form of a current to pressure transducer 40 includinga flexure or bender element 10 as in FIG. 1. Transducer housing 42includes an enclosed nozzle chamber 44 for containing fluid underpressure supplied through an inlet port 46 containing a primaryrestrictor 48. An outlet port 50 communicates with nozzle chamber 44 toprovide a fluid output pressure from transducer 40.

A nozzle 52 is mounted in housing 42 with a control nozzle end 54extending within nozzle chamber 44 and with an exhaust nozzle end 56communicating nozzle chamber 44 with an exhaust port 58.

Flexure element 10 is cantilever mounted in nozzle chamber 44 with freeclosed end 12 above the control nozzle end. In particular, flexureelement leg 14 is fixedly mounted to an abutment 60 to maintain flexureelement 10 in the position shown in FIG. 2. Leg 16 is connected to amovable magnetic core 62 at one end and with the other end of core 62being connected to a magnetostrictive rod 64 which in turn has itsopposite end mounted to magnetic housing 66.

Within magnetic housing 66, there is included a coil 68 surroundingmagnetostrictive rod 64 with the opposite coil ends connected torespective connecting wires 70 for receiving an electrical current.Magnetostrictive rod 64 can be formed of magnetostrictive material whichresponds to a magnetic field produced by current flowing in coil 68 toinduce a strain in the magnetostrictive material and thereby elongatethe material.

Such magnetostrictive material is well known and is normally formed ofalloys of rare earth elements with iron. Presently available rare earthmagnetostrictive materials produce large strains up to approximately2,000 ppm (parts per million) for an imposed magnetic field as a resultof a current in surrounding coil 68. In particular, it is preferred thatrod 64 be formed of a magnetostrictive material sold with the trademark"TERFENOL-D", which is currently available from Edge Technologies, Inc.of Ames, Iowa.

One end of nozzle chamber 44 is sealed by means of a flexible feedbackdiaphragm 72 which in turn is mounted to movable magnetic core 62. Thus,enclosed nozzle chamber 44 within housing 42 has openings through inletport 46, outlet port 50 and exhaust port 58 and is sealed at theopposite end by means of a flexible diaphragm 72. The outer perimeter ofdiaphragm 72 is mounted to housing 42 and the inner perimeter is mountedinto movable magnetic core 62. Feedback diaphragm 72 may be constructedof a thin metal material such as type 316 stainless steel.

Electromechanical transducer 40 transforms electrical energy in the formof an electrical current supplied to wires 70 into mechanical energy inthe form of fluid pressure supplied from fluid outlet port 50. Such atransducer is particularly useful in for instance an electronic controlloop where the final control element, generally a control valve, ispneumatically operated. Typically, the transducer receives a milliampereof direct current input signal such as on wires 70 and transmits aproportional pneumatic output pressure on output port 50 to a finalcontrol element which may control the flow of fluid in a fluid pipelinesystem.

In the operation of the present invention illustrated in FIGS. 2, 3, anelectrical current supplied to wires 70 and flowing in coil 68 producesa magnetostrictive strain in the magnetostrictive material formingmagnetostrictive rod 64 so as to elongate rod 64 and transmit thismicro-motion through feedback diaphragm 72 and movable magnetic core 62to leg 16 of bender 10. This linear micro-motion displacement of leg 16causes free closed end 12 of the flexure element to move toward controlnozzle end 54 with a greatly amplified motion as shown in FIG. 3.

As flexure element 10 moves toward nozzle 52, the fluid flow out exhaustnozzle end 56 and exhaust port 58 is restricted thereby resulting in anincrease in fluid pressure in nozzle chamber 44. The increased nozzlepressure in nozzle chamber 44 acts on feedback diaphragm 72 to result ina compressive force which tends to restore rod 64 to its originalposition. For reference purposes, FIG. 3 shows an exaggeratedillustration of the micro-movement x of leg 16. The feedback compressionagainst diaphragm 72 continues until the feedback force balances theelectrical input force inducing the movement of magnetostrictive rod 64to thereby establish an output pressure on fluid output port 50 which isproportional to the input current. Thus, bending of flexure element 10towards or away from control nozzle end 54 changes the fluid outputpressure on fluid output port 50 so as to change the pressure in nozzlechamber 44 acting against feedback diaphragm 72 and to change theresulting feedback force until the final fluid output pressure at pert50 is proportional to the electrical current value present at wires 70.

An alternative current to pressure transducer is shown in FIG. 4 whereinthe prior feedback on diaphragm 72 has been eliminated. In theembodiment of FIG. 4, the supply pressure is coupled to a T-fitting 74through a primary restrictor 76 and communicates with output line 78which terminates in a controlled pressure output port. In thisembodiment the output pressure on line 78 is directly responsive to theinput current value at wires 70. The output pressure in this case ismore sensitive to the input, but, without feedback, is less linear andless precise compared to the current to pressure transducer of FIGS. 2,3.

It is understood of course that in the illustrated bender elementembodiment of FIG. 1, either leg 14 or 16 can be fixed in position whilethe other le(g is moved so as to obtain the motion amplification andtranslation of small displacements. The flexure element 10 of thepresent invention is particularly useful when small, micron-sizeddisplacements are generated by magnetostrictive, electrostrictive orpiezoelectric devices. Such combinations find practical application inactuators and transducers, such as current to pressure transducers,electro-pneumatic relays, and control valve actuators.

Alternatively, both legs may be movable with respect to each other.Thus, for instance, if both legs are moved in the same direction thereis no transverse displacement of the closed end; and if both legs aremoved in opposite directions the closed end will be displaced in atransverse direction with amplified movement. Such a device may beutilized as a motion averaging or summing transducer unit wherein firstand second inputs can be coupled to a respective leg and the inputdisplacements generate amplified transverse movements of the free closedend corresponding to the difference between the two inputs.

Other application embodiments of a flexure or bender element inaccordance with this aspect of the invention are illustrated in FIGS.5-11. FIGS. 5-8 and 11 illustrate a flexure element in variousapplications using the motion amplification and translation features ofsuch a flexure element; FIG. 9 illustrates a flexure element toattenuate large motions and provide precise smaller motions forpositioning of surfaces or probes; and FIG. 10 illustrates a flexureelement embodiment used to sum pressure and motion inputs.

FIG. 5 illustrates an embodiment 79 having flexure or bender 10 withfixed leg 14 mounted to a stationery member such as fixed mounting block20, and with moving leg 16 coupled to a diaphragm 80 through aconnecting flange 82. The diaphragm is mounted in block 20 so as toprovide an enclosed pressure chamber 84 receiving an input fluidpressure through an inlet 86. The pressure at inlet 86 and in chamber 84acts on diaphragm 80 to move leg 16 in directions A or B to providemotion amplification and translation along respective directions C or D.Thus, the bender embodiment of FIG. 5 converts pressure to motion usinga single diaphragm.

FIG. 6 illustrates another bender application embodiment 87 in which thebender element converts pressure to motion using a bellows 88 to whichis coupled a fluid pressure through inlet 86. FIG. 7 illustrates anotherbender embodiment 89 which is responsive to both input fluid pressure oninlet 86 and input fluid pressure on inlet 90 and converts the outputmotion along respective directions C, D using a diaphragm stack. A firstenclosed chamber 84 in fixed mounting block 20 is provided by diaphragm80. A second chamber 92 is provided by diaphragm 94 wherein fluidpressure inlet 90 communicates with chamber 92.

FIG. 8 illustrates another embodiment 96 in which a flexure or benderelement 10 is used to operate a spool valve 98. Fixed leg 14 is mountedto fixed mounting block 20 and moving leg 16 is connected through asuitable drive means to cause motion displacements along directions A,B. Closed end 12 is mounted to valve rod 100 to thereby move the valvemembers 101 along directions C, D in response to input motions A, B.Operating valve rod 100 along motion directions C, D, respectivelycouples the supply pressure in spool valve 98 to output pressure 1 oroutput pressure 2.

The flexure element application embodiment 102 of FIG. 9 provides motionattenuation rather than motion amplification. Fixed leg 14 is againmounted to a fixed mounting block 20. Movable leg 16 is mounted to afree end 103 of a flexible member 105 having the opposite end 107 fixedin position by mounting to a fixed mounting block 20. Typically, flexingor pivoting end 103 would include a special surface, probe, switchelements, or other devices utilizing the small output displacement indirections A, B of end 103 in response to large motion inputs indirections C, D at flexure element closed end 12. Accordingly, in thisaspect of the invention, a bender element 10 is used to provide precisemotion attenuation for precise positioning of laser mirrors, etc. onmoving end 103.

Referring now to FIG. 10, there is illustrated an alternativeapplication embodiment 104 using a bender element 11 with legs 16, 17each of which is movable with respect to each other to provide anamplified translated motion along directions C, D. Moving leg 16 ismounted to bellows 88 receiving fluid pressure through inlet line 86.Longitudinal displacements along directions A, B are therefore in directresponse to the pressure at inlet line 86. Movable leg 17 also may bedisplaced longitudinally along directions A', B' in response to a drivemotion means connected to end 23 of leg 17. Thus, flexure element closedend 12 moves in directions C, D in response to the difference betweenthe motion inputs to legs 16, 17.

For example, if the legs 16, 17 are moved in respective directions A,B', closed end 12 moves in amplified transverse direction C. If the legsare moved in directions A', B, closed end 12 moves in direction D. Ifthe legs are moved in respective directions A, A' or B, B', closed end12 does not move in the transverse direction.

In the example of embodiment 104 shown in FIG. 10, leg 17 is displacedby means of the movements of a platform 106 having a rotating wheel 108in contact with cam surface 110 of an eccentric cam 112. Eccentric cam112 is fixed to and driven by a rotatable shaft 114 which is rotatablymounted in a fixed frame 116. Thus, as shaft 114 is rotated in theindicated clockwise or counter-clockwise directions, eccentric cam 12 isrotated to move plate 106 upwardly or downwardly, thereby providing thedisplacement motions of leg 17 along directions A', B'. A hinge member118 may be used to connect plate 106 to a fixed frame 120.

Nozzle 122 is mounted adjacent closed end 12 and is supplied with afluid flow. Thus, the fluid flow and pressure at nozzle 122 iscontrolled by the movement of closed end 12 in directions C, D. In theillustration of embodiment 104 shown in FIG. 10, bender element 11 isresponsive to the pressure at input 86 and the motion input on shaft114. Embodiment 104 therefore has applications in the construction ofprocess controllers and valve positioners.

FIG. 11 illustrates another embodiment 130 comprising a proportionalsolenoid current to pressure transducer. Embodiment 130 includes abender element 10 for converting an electric current into a variableflow rate from nozzle outlet 132 using a solenoid 134. Fixed leg 14 ismounted to a rigid, fixed portion of solenoid 134. Displaceable leg 16is mounted to a free end of solenoid armature 136 with the other endbeing hingedly mounted to the solenoid by hinge means 138. A source ofpneumatic pressure is coupled to a T-fitting 140 through a fixedmetering orifice or primary restrictor 142 and communicates with outputline 146 which terminates in a controlled pressure output port.

In operation, the proportional current to pressure transducer makes useof the flexure 10 to minimize the amount of travel required of thesolenoid's armature. Reduced armature travel allows the solenoid to bedesigned to operate in a stable region and therefore act in aproportional manner in response to changes in electrical current ratherthan the snap acting manner commonly associated with solenoid operation.The solenoid armature 136 slowly moves towards and away from thesolenoid 134 in response to the input solenoid coil current due to thestiffness of element 10. These small motion displacements alongdirections A, B are translated into amplified displacements C, D ofclosed end 12 to provide a variable flow rate from nozzle 132. Thisembodiment eliminates the hysteresis due to pivots, bearings, etc.commonly encountered in other transducer designs.

The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

We claim:
 1. An electromechanical transducer providing a fluid outputpressure proportional to an electrical input signal comprising:a flexureelement having a closed end and two legs extending therefrom alongrespective longitudinal axes; means for fixedly mounting one of saidlegs; solenoid means including a solenoid coil developing a magneticfield in the absence of a permanent magnet, a non-permanent magnetsolenoid armature, said solenoid armature moveable in response to saidelectrical input signal supplied to the solenoid coil, and meansmounting the solenoid armature to the other of said legs to displaceablymove said other leg in micron-sized longitudinal displacements inresponse to said electrical input signal; said longitudinal displacementmovement of said other leg being amplified and translated into largertransverse movement of said closed end with respect to said longitudinalaxis, fluid pressure means including a nozzle having a nozzle outletlocated immediately adjacent said flexure element closed end forsupplying fluid pressure to said flexure element, said fluid pressure atsaid nozzle outlet being more or less restricted by movement of saidclosed end towards or away from said nozzle outlet in response to saidelectrical input signal; said fluid pressure means further including afluid pressure outlet line coupled to said nozzle and terminating in acontrolled pressure output port so the fluid output pressure at thecontrolled pressure output port is proportional to the electrical inputsignal.
 2. An electromechanical transducer according to claim 1, whereinsaid solenoid armature is enabled to slowly move towards and away fromsaid solenoid in response to said electrical input signal.
 3. Anelectromechanical transducer according to claim 1, wherein said flexureelement is U-shaped.
 4. An electromechanical transducer providing afluid output pressure proportional to an electrical input signalcomprising:a flexure element having a closed end and two legs extendingtherefrom along respective longitudinal axes; electrical coil meanscoupled to one of said legs for displaceably moving said one leg withrespect to the other of said legs in micron-sized longitudinaldisplacements along its longitudinal axis to enable the flexure elementto selectively bend towards or away from said longitudinal axis withflexing of the flexure element legs distributed along their respectivelengths, said electrical coil means includes solenoid means including asolenoid coil developing a magnetic field in the absence of a permanentmagnet, a non-permanent magnet solenoid armature, said solenoid armaturemoveable in response to said electrical input signal supplied to thesolenoid coil, and means mounting the solenoid armature to said one legto displaceably move said one leg in response to said electrical inputsignal; said longitudinal displacement movement of said one leg beingamplified and translated into larger transverse movement of said closedend with respect to said longitudinal axis, fluid pressure meansincluding a nozzle having a nozzle outlet located immediately adjacentsaid flexure element closed end for supplying fluid pressure to saidflexure element, said fluid pressure at said nozzle outlet being more orless restricted by movement of said closed end toward or away from saidnozzle outlet in response to said electrical input signal; said fluidpressure means further including a fluid pressure outlet line coupled tosaid nozzle and terminating in a controlled pressure output port so thefluid output pressure of the controlled pressure output port isproportional to the electrical input signal.
 5. An electromechanicaltransducer according to claim 4, wherein said solenoid armature isenabled to slowly move towards and away from said solenoid in responseto said electrical input signal.
 6. An electromechanical transduceraccording to claim 4, wherein said flexure element is U-shaped.